Cost effective b20 performance upgrades

[tonydgray]

Hi all

I'm in the process of sorting my 145 out for the mot and for this I need to rectify my blowing exhaust. With that in mind that I would ideally like to do a couple of fairly cheap mods to make the B20 a bit more lively so I want to make sure I get the right exhaust now. I like the GES ones due to the stainless element but am I right in thinking they are a standard replacement, that's what the lady implied on the phone anyhow. I've also been looking at Simons exhaust as there is and option to couple it to a tubular manifold later on which is the kind of thing I'm looking for.

I am open to any recommendations like carbs, cams etc but I don't really know how much and what fairly simple mods would work.

Looking forward to your ideas, cheers Tony

[arcturus]

I don't think that sport exhaust is worth while unless you have a gas flowed head, but it won't do any harm.

[Burdekin]

What engine have you got ie is it a B20E engine? If it isn't then if you can locate a B20E head that will be a really good start with the E exhaust manifold. A wee port and polish of the head would improve things as well and you could also consider hardened exhaust seats and slightly larger exhaust valves are recommended as well. If you can afford it a KG10 cam will go well with the above but don't forget to price in new followers and push rods etc.

If going for a tubular manifold, do your engine build first and then decide what size and design of manifold to go for. The KG trimming type 1 is plenty large enough for what I recommended above and will still give you good low down power. I think the KG type 1 is probably equivalent to the old Volvo type R manifold. But also for the above, the E manifold is ideal.

[classicswede]

As you have the B20A then there are lot of fairly cheap things you can do to improve power output.

Exhaust wise I used t recomend and sell the Simons sport systems, however teh quality has gne down hill and they are short lived. We no offer stainless sports systems fabricated in Wales. The exhaust is step one to improvements.

The tubular 4 branch manifold does offer a fair improvment but bang for your buck is not very good. If doing a budget build the manifold will not be on your list of wants. Best bet would be to seperate the inlet and exhaust manifold to reduce heat soak.

The normal upgrade for single carb engines is to convert to twin carbs. The maniflds and carbs can be obtained used for a reasonable price but bank n rebuilding the carbs. Twin carbs are not to everyones tast. I am working on a single carb manifold with improved flow to get the flow of the twin manifold without the hassle of two carbs. For best power converting to webbers or similar is the way to go as long as you are not worried about how much fuel you use!

Cam wise with the single carb I would go for the D or K cam especialy if you plan on towing. KG also offer cams but I personaly have no experiance of them yet to fully comment.

Head wise a basic port and if budget will allow E inlet valves and increased size exhaust valves combine with unleaded valve guides.

[Burdekin]

Forgot to say a lightened flywheel is another excellent improvement and before anyone says that it makes it harder to drive around town, that is total BS, maybe an aluminium one that had no mass. I took 3.5kg off my flywheel and the engine responds much better, the original flywheel was well overdesigned weight wise.

[arcturus]

I know that 144's will not set the world on fire but at the end of the day they are old ladies and I think that they should be treated as such unless you are into competition. Perhaps the cheapest mod would be a really good service making sure that everything is in top condition and working eficiently. New points plugs and even a high performance coil. Just my opinion.

[classicswede]

Originally Posted by arcturus

Perhaps the cheapest mod would be a really good service making sure that everything is in top condition and working eficiently. New points plugs and even a high performance coil. Just my opinion.

Yes a stage 0 tune is a must before doing anything else.

Lightened flywheel is worth while. The alu would not be a cost effective mod but maching would be.

[john h]

http://www.youtube.com/watch?v=fqzDCkZh7fM

[tonydgray]

Originally Posted by john h

http://www.youtube.com/watch?v=fqzDCkZh7fM

Very nice!!